Objective: To investigate the hematological characteristics of co-inheritance of α-thalassemia (α-thal) and β-thalassemia (β-thal) and to survey the incidence of co-inheritance of α-thal and β-thal in Guangxi.
Methods: DNA samples from 370 primary and middle school students who were β-thal carriers in Guangxi were further processed for the α-goblin gene mutation screening, and were grouped based on the genotype of β- and α-goblin gene. The hematological indexes to the different groups were compared by One-way ANOVA.
Results: Of the total 370 β-thal carriers, 79 were found to carry α-thal, which gave a frequency of 21.35% for β-thal carriers and 1.36% for coincidence of these two common disorders in the local population. As expected, the 79 patients presented very variable α-globin alterations in combination with β-globin mutations, showing 31 genotype combined with the coincidence of both Hb disorders. Except the genotypes of 3 β-thal heterozygotes combined with ααα(anti3.7) triplication and 2 β-thal carriers with IVS-II-654(C→T)/N combined-α(3.7)/αα presented the phenotype of thalassemia intermedia, and other 74 carriers with co-inheritance of α-thal and β-thal all presented the phenotype of β-thal trait. There were significant differences between β-thal heterozygotes and the carriers with a co-inheritance of both β+α(0) thal in MCH, MCV and Hb. In addition, there existed significant difference between the carriers with a co-inheritance of both β+α(+) thal and a co-inheritance of both β+α(0) thal in MCV, MCH and Hb.
Conclusion: Compared to that of β-thal heterozygotes, the carriers with a co-inheritance of α-thal and β-thal had slighter phenotype with hematological characteristics. It's difficult to distinguish the double heterozygotes with the co-inheritance of α-thal and β-thal from β-thal heterozygotes by hematological indexes, the molecular diagnosis should be performed.